1. Field of the Invention
The present invention relates to a back light module, and more specifically, to a backlight module with a diffusing particle structure.
2. Description of the Prior Art
Since liquid crystal molecules do not produce light themselves, a common method for driving an LCD to display images involves utilizing a backlight module to provide light with sufficient brightness and uniform distribution to the LCD. Therefore, a backlight module is one of the major components of an LCD. A traditional backlight module uses a cold cathode fluorescent lamp (CCFL) or an LED (Light Emitting Diode) as a light source. Both CCFL light sources and LED light sources have respective advantages and drawbacks. For example, a CCFL light source has an advantage of high brightness, but its color temperature is only about 4800K, thereby limiting color performance of the LCD. On the other hand, an LED light source has advantages of high color saturation, vivid color gamut, and long life. However, for an LED, a control problem occurs due to mixing of natural light. Furthermore, a display problem known as a “Hot Spot” is caused by an emitting angle of the LED. As mentioned above, the applications of the CCFL light source and the LED light source are limited due to the said drawbacks. Therefore, another enhanced method of utilizing a laser as a light source of a backlight module is available. In this method, light with ultra-high color saturation and ultra-vivid color gamut may be achieved through coherence and monochromaticity of the laser, so that color performance of the LCD may be increased accordingly.
In the prior art, a common method of utilizing a laser as a light source of a backlight module is to use a fiber-optic tube for conducting a laser beam emitted from a laser light source. Please refer to FIG. 1, which is a diagram of a backlight module 10 with a laser light source according to the prior art. The backlight module 10 comprises a laser light source 12, a fiber-optic tube 14, a fluorescent layer 16, and a light guide plate 18. As shown in FIG. 1, a plurality of groove structures 20 is formed inside the fiber-optic tube 14. As a result, the laser beam may be incident to the fluorescent layer 16 via being totally reflected by the inner wall of the fiber-optic tube 14 and reflected by the groove structures 20 in FIG. 1. After the laser beam passes through the fluorescent layer 16, the light guide plate 18 may receive a processed laser beam so that subsequent light processing procedures may continue. However, when the laser beam is reflected by the groove structures 20, scattering of the laser beam may occur at the same time so as to cause loss of light, thereby causing poor uniformity and low coupling efficiency of the light beam incident to the light guide plate 18.